[HawgRyder]

Quickest check that I know of: with engine turned off...check battery voltage (should be at least 12.2V)...then..start engine...check battery voltage again (at battery)...should be more then 12.2V....if not...you have a problem.
Then...altenators use a feedback system to excite the stator coils...if you feed 12v (battery voltage) to this terminal at the altenator...it will output full voltage...only do this for a very short time.
If the alt puts out big volts (could be as much as 16V) then the alt is good and the reg is bad.
Bob